Perhaps you should try some spelling variations:
trinh van » trinh han, trinh quan, trinh toan
coc thuc » hoc thuc, doc thuc, co thuc
thuc va » thuc vat, thuc dan, thuc day
tinh va » tich va, trinh vat, tinh gia
su sach » so sach, vu sach
hieu ve » hieu va, hieu van
ky tang » ky nang, kho tang, ky trong
ky dang » ky nang, ky danh
cua tre » cua te, cuu tre, cua triet
ve coc » ve cuoc, ve cac, ve co

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ((ky dang) or (ky tang)) xa hoi. hieu ve coc thuc va ((tinh va) OR (trinh van)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((ky dang) OR (ky tang)) xa hoi. hieu ve coc thuc va ((tinh va) OR (trinh van)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ((ky dang) or (ky tang)) xa hoi. hieu ve coc thuc va ((tinh va) OR (trinh van)) cua tre".
• Adding a wildcard symbol may retrieve word variants: su sach ((ky dang) or (ky tang)) xa hoi. hieu ve coc thuc va ((tinh va) OR (trinh van)) cua tre*.